Transformer



- March 29, 1938. H. BURNHAM TRANSFORMER Filed Sept. 26, 1 936 a|l||l|l|l|1|||||lI J 1 T u u n 1 .IIIIIIIIL Inventor; Locke flBuvnhamHis Attor ey phenol M... 29, 1938 2,112,733

UNITED STATES PATENT OFFICE TRANSFORMER Locke H. Burnham, Pittsileld,Mass" alsignor to General Electric Company, a corporation of New YorkApplication September 26, 1938, Serial No. 102,723

' z Claims- (Cl. 115-401) My invention relates to transformers and, moremotor is. Cooling air may thus be forced through particularly, to thattype of transformer which the tubes I by the blower II. An outlet maniisimmersed in an insulating and cooling liquid. fold 20 and pipe 2| may beprovided if desired to The losses in a transformer appear as heat,conduct away the air from the other ends of the 5 which increases thetemperature of the transtubes where they open through the opposite wall5 former, and the maximum load capacity of the of the casing 12.transformer is limited by the maximum tempera- During operation of thetransformer, the losses ture which it can safely withstand withoutinjury. in the transformer appear as heat, which is ab- The maximumcapacity of the transformer can sorbed by the adjacent liquid l i. Thisheated be increased by increasing the rate at which the liquid rises byconvection toward the top of the 10 heat is dissipated. The generalobject of the casing I2 where it passes along the surfaces of thepresent' invention is to provide an improved artubes H. The heat isabsorbed by the tubes and rangement for rapidly and eilectivelydissipating finally by the cooling air flowing through them, the 'heatfrom a liquid-immersed transformer. this air carrying the heat rapidlyaway. The

The invention will be better understood from cooled liquid then descendsalong the walls of 15 the following description taken in connection thecasing to the bottom of the transformer where with the accompanyingdrawing in which Fig. 1 it is ready to rise again and absorb more heatshows a liquid-immersed transformer constructed from the transformer. inaccordance with my invention, part of the with the arrangement which hasbeen decasing being broken away to reveal details, and scribed, thecooling tubes I are located entirely 20 Fig. 2 is another view of thetransformer shown in in the upper, and therefore the hottest, part ofFig. 1, part of the casing being also broken away the liquid I I wherethere is the greatest diiference to reveal details. in'temperaturebetween the'tubes and the liquid Like reference characters indicatesimilar parts and where the heat-absorbing efficiency of the in bothfigures of the drawing. tubes is therefore greatest. When the transform-25 The transformer ll, shown in the drawing, er is carrying full loadand the liquid II is fully is immersed in a body of insulating andcooling expanded, it is desirable that the level of the liquid llcontained in-a metal casing II. The liquid be slightly above the upperedges of the liquid II will expand and contract in response to tubes.When the transformer is'carrying no load,

0 changes in temperature and the space ll above or only partial load, sothat the liquid ii is only the liquid, preferably filled with an inertgas, such partially expanded, then the upper edges of the 1 as drynitrogen, is provided to permit such expantubes I may extend above thelevel of the liquid sion and contraction of the liquid. The casing 12because under these conditions their maximum may be sealed from theoutside air, the volume heat-absorbing efliciency is not necessary.

0f the space H ei Silihcient to P ve t e ces- The invention has beenexplained by describing 35 sive pressure under maximum conditions oftemand illustrating a particular arrangement for peratureand expansionof the liquid. effectively cooling a liquid-immersed transformer A p ual y of m t t s H are a s but it will be obvious that changes may bemade horizonta y-i e u p p f the liquid ll without departing from thespirit of the inven- 40 above the transformer ll. Each of these tubes tand th scope 1 th appended l s, 40

extends throu h oppo Side wflllfl 0f the 8 What I claim as new anddesire to secure by ,1 d u comm into; at each end with the LettersPatent of the United States, is:- outside air. The tubes ll are parallelh 1. The combination with a transformer im- O r and Spaced p and arePreferably mersed in a cooling liquid within a casing, of a to d wi htheir greatest diameters arranged gas space above the liquid, wherebythe level of 45 t a ly- T y r als pr f ra y a r s the liquid will varyin response to temperature th t their upper edges extend above the levell5 changes of the liquid, a plurality of spaced tubes of the liquid IIwhen the liquid is cold but so arranged horizontally in the upper partof said t t t y are completely immersed in the liquid liquid and openingthrough opposite sides of the and below its level it when the liquid isfully casing, the upper portions of the tubes being 10- 5 expanded andthe transformer is carrying its cated between the maximum and theminimum maximum safe load. The ends of the tubes ll, levels of theliquid, and means for blowing cooling opening through one side of thetransformer cas air through the tubes. 4 ing II, are covered by amanifold il which is 2. The combination with a transformer inrconnectedto a blower or fan It operated by a mersedin a cooling liquid within acasing, of a 5 5 part of said liquid and opening through opposite sidesof the casing, the tubes beinglocated with their upper edges between themaximum and minimum levels of the liquid and with their greatestdiameters vertical, and means for blowing cooling air through the tubes.

LOCKE H. BURNHAM.

